Search Results

Search found 378 results on 16 pages for 'gravity'.

Page 4/16 | < Previous Page | 1 2 3 4 5 6 7 8 9 10 11 12  | Next Page >

  • sprite animation system height recalculating has some issues

    - by Nicolas Martel
    Basically, the way it works is that it update the frame to show every let's say 24 ticks and every time the frame update, it recalculates the height and width of the new sprite to render so that my gravity logics and stuff works well. But the problem i am having now is a bit hard to explain in words only, therefore i will use this picture to assist me The picture So what i need basically is that if let's say i froze the sprite at the first frame, then unfreeze it and freeze it at the second frame, have the second frame's sprite (let's say it's a prone move) simply stand on the foothold without starting the gravity and when switching back, have the first sprite go back on the foothold like normal without being under the foothold. I had 2 ideas on doing this but I'm not sure it's the most efficient ways to do it so i wanna hear your inputs.

    Read the article

  • Box 2D Collision Question

    - by Farooq Arshed
    I am very new to Box 2D Physics world. I wanted to know how to collide 2 bodies when one is Dynamic and other is Kinematic. The whole Scenario is explained below: I have 3 balls in total. I want to balls to remain in their places and the third ball to be able to move. When the third ball hits the other two balls then they should move according to the speed and direction from which they were hit. My gravity of the world is 0 because I only want z-axis gravity. I would also like some one to point me towards some good tutorials regarding Box 2D basics which is language independent. I hope I have explained my scenario well. Thanks for the help in advance.

    Read the article

  • Cocos2d: carom like game

    - by Raj
    Now I am working on carrom like game using cocos2d+Box2d. I set world gravity(0,0), want gravity in z - axis. I set following value for coin striker body: Coin body: density = 20.0f; friction = 0.4f; restitution = 0.6f; Shape Circle with radius - 15/PTM_RATIO Striker body: density = 25.0f; friction = 0.6f; restitution = 0.3f; Shape Circle with radius - 15/PTM_RATIO Output is not smooth, when I apply ApplyLinearImpulse(force,position); Coin movement looks like floating in air....takes too much time to stop... Which value of coin and striker makes it look like real carom?

    Read the article

  • Floating point precision and physics calculations

    - by Vee
    The gravity Vector2 in my physics world is (0; 0.1). The number 0.1 is known to be problematic, since "it cannot be represented exactly, but is approximately 1.10011001100110011001101 × 2-4". Having this value for the gravity gives me problems with collisions and creates quite nasty bugs. Changing the value to 0.11 solves these problems. Is there a more elegant solution that doesn't require changing the value at all?

    Read the article

  • How do I make a jumping dolphin rotate realistically?

    - by Johnny
    I want to program a dolphin that jumps and rotates like a real dolphin. Jumping is not the problem, but I don't know how to make the rotation. At the moment, my dolphin rotates a little weird. But I want that it rotates like a real dolphin does. How can I improve the rotation? public class Game1 : Microsoft.Xna.Framework.Game { GraphicsDeviceManager graphics; SpriteBatch spriteBatch; Texture2D image, water; float Gravity = 5.0F; float Acceleration = 20.0F; Vector2 Position = new Vector2(1200,720); Vector2 Velocity; float rotation = 0; SpriteEffects flip; Vector2 Speed = new Vector2(0, 0); public Game1() { graphics = new GraphicsDeviceManager(this); Content.RootDirectory = "Content"; graphics.PreferredBackBufferWidth = 1280; graphics.PreferredBackBufferHeight = 720; } protected override void Initialize() { base.Initialize(); } protected override void LoadContent() { spriteBatch = new SpriteBatch(GraphicsDevice); image = Content.Load<Texture2D>("cartoondolphin"); water = Content.Load<Texture2D>("background"); flip = SpriteEffects.None; } protected override void Update(GameTime gameTime) { float VelocityX = 0f; float VelocityY = 0f; float time = (float)gameTime.ElapsedGameTime.TotalSeconds; KeyboardState kbState = Keyboard.GetState(); if(kbState.IsKeyDown(Keys.Left)) { rotation = 0; flip = SpriteEffects.None; VelocityX += -5f; } if(kbState.IsKeyDown(Keys.Right)) { rotation = 0; flip = SpriteEffects.FlipHorizontally; VelocityX += 5f; } // jump if the dolphin is under water if(Position.Y >= 670) { if (kbState.IsKeyDown(Keys.A)) { if (flip == SpriteEffects.None) { rotation += 0.01f; VelocityY += 40f; } else { rotation -= 0.01f; VelocityY += 40f; } } } else { if (flip == SpriteEffects.None) { rotation -= 0.01f; VelocityY += -10f; } else { rotation += 0.01f; VelocityY += -10f; } } float deltaY = 0; float deltaX = 0; deltaY = Gravity * (float)gameTime.ElapsedGameTime.TotalSeconds; deltaX += VelocityX * (float)gameTime.ElapsedGameTime.TotalSeconds * Acceleration; deltaY += -VelocityY * (float)gameTime.ElapsedGameTime.TotalSeconds * Acceleration; Speed = new Vector2(Speed.X + deltaX, Speed.Y + deltaY); Position += Speed * (float)gameTime.ElapsedGameTime.TotalSeconds; Velocity.X = 0; if (Position.Y + image.Height/2 > graphics.PreferredBackBufferHeight) Position.Y = graphics.PreferredBackBufferHeight - image.Height/2; base.Update(gameTime); } protected override void Draw(GameTime gameTime) { GraphicsDevice.Clear(Color.CornflowerBlue); spriteBatch.Begin(); spriteBatch.Draw(water, new Rectangle(0, graphics.PreferredBackBufferHeight -100, graphics.PreferredBackBufferWidth, 100), Color.White); spriteBatch.Draw(image, Position, null, Color.White, rotation, new Vector2(image.Width / 2, image.Height / 2), 1, flip, 1); spriteBatch.End(); base.Draw(gameTime); } } I changed my code a little. But I still have some trouble with the rotation. Here's the entire code. The dolphin looks at the wrong direction if I press the left or right key. For example, it looks down if I press the left key. What is wrong with the rotation? At the beginning, the dolphin looks at the left side, but after I pressed a key it just looks down or up. I deleted the "rotation += 0.01f;" lines in the code. Is that correct? public class Game1 : Microsoft.Xna.Framework.Game { GraphicsDeviceManager graphics; SpriteBatch spriteBatch; Texture2D image, water; float Gravity = 5.0F; float Acceleration = 20.0F; Vector2 Position = new Vector2(1200,720); Vector2 Velocity; float rotation = 0; SpriteEffects flip; Vector2 Speed = new Vector2(0, 0); Vector2 prevPos; public Game1() { graphics = new GraphicsDeviceManager(this); Content.RootDirectory = "Content"; graphics.PreferredBackBufferWidth = 1280; graphics.PreferredBackBufferHeight = 720; } protected override void Initialize() { base.Initialize(); } protected override void LoadContent() { spriteBatch = new SpriteBatch(GraphicsDevice); image = Content.Load<Texture2D>("cartoondolphin"); water = Content.Load<Texture2D>("background"); flip = SpriteEffects.None; } protected override void Update(GameTime gameTime) { float VelocityX = 0f; float VelocityY = 0f; float time = (float)gameTime.ElapsedGameTime.TotalSeconds; KeyboardState kbState = Keyboard.GetState(); if(kbState.IsKeyDown(Keys.Left)) { flip = SpriteEffects.None; VelocityX += -5f; } if(kbState.IsKeyDown(Keys.Right)) { flip = SpriteEffects.FlipHorizontally; VelocityX += 5f; } rotation = (float)Math.Atan2(Position.X - prevPos.X, Position.Y - prevPos.Y); prevPos = Position; // jump if the dolphin is under water if(Position.Y >= 670) { if (kbState.IsKeyDown(Keys.A)) { if (flip == SpriteEffects.None) { VelocityY += 40f; } else { VelocityY += 40f; } } } else { if (flip == SpriteEffects.None) { VelocityY += -10f; } else { VelocityY += -10f; } } float deltaY = 0; float deltaX = 0; deltaY = Gravity * (float)gameTime.ElapsedGameTime.TotalSeconds; deltaX += VelocityX * (float)gameTime.ElapsedGameTime.TotalSeconds * Acceleration; deltaY += -VelocityY * (float)gameTime.ElapsedGameTime.TotalSeconds * Acceleration; Speed = new Vector2(Speed.X + deltaX, Speed.Y + deltaY); Position += Speed * (float)gameTime.ElapsedGameTime.TotalSeconds; Velocity.X = 0; if (Position.Y + image.Height/2 > graphics.PreferredBackBufferHeight) Position.Y = graphics.PreferredBackBufferHeight - image.Height/2; base.Update(gameTime); } protected override void Draw(GameTime gameTime) { GraphicsDevice.Clear(Color.CornflowerBlue); spriteBatch.Begin(); spriteBatch.Draw(water, new Rectangle(0, graphics.PreferredBackBufferHeight -100, graphics.PreferredBackBufferWidth, 100), Color.White); spriteBatch.Draw(image, Position, null, Color.White, rotation, new Vector2(image.Width / 2, image.Height / 2), 1, flip, 1); spriteBatch.End(); base.Draw(gameTime); } }

    Read the article

  • How do I run gtk demos?

    - by Runner
    They are located under: share\gtk-2.0\demo But none of them contains a main function, how can I make the following textscroll.c actually work: /* Text Widget/Automatic scrolling * * This example demonstrates how to use the gravity of * GtkTextMarks to keep a text view scrolled to the bottom * while appending text. */ #include <gtk/gtk.h> #include "demo-common.h" /* Scroll to the end of the buffer. */ static gboolean scroll_to_end (GtkTextView *textview) { GtkTextBuffer *buffer; GtkTextIter iter; GtkTextMark *mark; char *spaces; static int count; buffer = gtk_text_view_get_buffer (textview); /* Get "end" mark. It's located at the end of buffer because * of right gravity */ mark = gtk_text_buffer_get_mark (buffer, "end"); gtk_text_buffer_get_iter_at_mark (buffer, &iter, mark); /* and insert some text at its position, the iter will be * revalidated after insertion to point to the end of inserted text */ spaces = g_strnfill (count++, ' '); gtk_text_buffer_insert (buffer, &iter, "\n", -1); gtk_text_buffer_insert (buffer, &iter, spaces, -1); gtk_text_buffer_insert (buffer, &iter, "Scroll to end scroll to end scroll " "to end scroll to end ", -1); g_free (spaces); /* Now scroll the end mark onscreen. */ gtk_text_view_scroll_mark_onscreen (textview, mark); /* Emulate typewriter behavior, shift to the left if we * are far enough to the right. */ if (count > 150) count = 0; return TRUE; } /* Scroll to the bottom of the buffer. */ static gboolean scroll_to_bottom (GtkTextView *textview) { GtkTextBuffer *buffer; GtkTextIter iter; GtkTextMark *mark; char *spaces; static int count; buffer = gtk_text_view_get_buffer (textview); /* Get end iterator */ gtk_text_buffer_get_end_iter (buffer, &iter); /* and insert some text at it, the iter will be revalidated * after insertion to point to the end of inserted text */ spaces = g_strnfill (count++, ' '); gtk_text_buffer_insert (buffer, &iter, "\n", -1); gtk_text_buffer_insert (buffer, &iter, spaces, -1); gtk_text_buffer_insert (buffer, &iter, "Scroll to bottom scroll to bottom scroll " "to bottom scroll to bottom", -1); g_free (spaces); /* Move the iterator to the beginning of line, so we don't scroll * in horizontal direction */ gtk_text_iter_set_line_offset (&iter, 0); /* and place the mark at iter. the mark will stay there after we * insert some text at the end because it has right gravity. */ mark = gtk_text_buffer_get_mark (buffer, "scroll"); gtk_text_buffer_move_mark (buffer, mark, &iter); /* Scroll the mark onscreen. */ gtk_text_view_scroll_mark_onscreen (textview, mark); /* Shift text back if we got enough to the right. */ if (count > 40) count = 0; return TRUE; } static guint setup_scroll (GtkTextView *textview, gboolean to_end) { GtkTextBuffer *buffer; GtkTextIter iter; buffer = gtk_text_view_get_buffer (textview); gtk_text_buffer_get_end_iter (buffer, &iter); if (to_end) { /* If we want to scroll to the end, including horizontal scrolling, * then we just create a mark with right gravity at the end of the * buffer. It will stay at the end unless explicitely moved with * gtk_text_buffer_move_mark. */ gtk_text_buffer_create_mark (buffer, "end", &iter, FALSE); /* Add scrolling timeout. */ return g_timeout_add (50, (GSourceFunc) scroll_to_end, textview); } else { /* If we want to scroll to the bottom, but not scroll horizontally, * then an end mark won't do the job. Just create a mark so we can * use it with gtk_text_view_scroll_mark_onscreen, we'll position it * explicitely when needed. Use left gravity so the mark stays where * we put it after inserting new text. */ gtk_text_buffer_create_mark (buffer, "scroll", &iter, TRUE); /* Add scrolling timeout. */ return g_timeout_add (100, (GSourceFunc) scroll_to_bottom, textview); } } static void remove_timeout (GtkWidget *window, gpointer timeout) { g_source_remove (GPOINTER_TO_UINT (timeout)); } static void create_text_view (GtkWidget *hbox, gboolean to_end) { GtkWidget *swindow; GtkWidget *textview; guint timeout; swindow = gtk_scrolled_window_new (NULL, NULL); gtk_box_pack_start (GTK_BOX (hbox), swindow, TRUE, TRUE, 0); textview = gtk_text_view_new (); gtk_container_add (GTK_CONTAINER (swindow), textview); timeout = setup_scroll (GTK_TEXT_VIEW (textview), to_end); /* Remove the timeout in destroy handler, so we don't try to * scroll destroyed widget. */ g_signal_connect (textview, "destroy", G_CALLBACK (remove_timeout), GUINT_TO_POINTER (timeout)); } GtkWidget * do_textscroll (GtkWidget *do_widget) { static GtkWidget *window = NULL; if (!window) { GtkWidget *hbox; window = gtk_window_new (GTK_WINDOW_TOPLEVEL); g_signal_connect (window, "destroy", G_CALLBACK (gtk_widget_destroyed), &window); gtk_window_set_default_size (GTK_WINDOW (window), 600, 400); hbox = gtk_hbox_new (TRUE, 6); gtk_container_add (GTK_CONTAINER (window), hbox); create_text_view (hbox, TRUE); create_text_view (hbox, FALSE); } if (!gtk_widget_get_visible (window)) gtk_widget_show_all (window); else gtk_widget_destroy (window); return window; }

    Read the article

  • Making AI jump on a spot effectively

    - by Pasquale Sada
    How to calculate, in 3D environment, the closest point, from which an AI character can jump onto a platform? Setup I have an initial velocity V(Vx,Vy,VZ) and a spot where the character stands still at S(Sx,Sy,Sz). What I'm trying to achieve is a successful jump on a spot E(Ex,Ey,Ez) where you have clicked on(only lower or higher spot, because I've in place a simple steering behavior for even terrains). There are no obstacles around. I've implemented a formula that can make him jump in a precise way on a spot but you need to declare an angle: the problem arise when the selected spot is straight above your head. It' pretty lame that the char hang there and can reach a thing that is 1cm above is head. I'll share the code I'm using: Vector3 dir = target - transform.position; // get target direction float h = dir.y; // get height difference dir.y = 0; // retain only the horizontal direction float dist = dir.magnitude ; // get horizontal distance float a = angle * Mathf.Deg2Rad; // convert angle to radians dir.y = dist * Mathf.Tan(a); // set dir to the elevation angle dist += h / Mathf.Tan(a); // correct for small height differences // calculate the velocity magnitude float vel = Mathf.Sqrt(dist * Physics.gravity.magnitude / Mathf.Sin(2 *a)); return vel * dir.normalized; Ended up using the lowest angle (20 degree) and checking for collision on the trajectory. If found any increase the angle. Here some code (to improve the code maybe must stop the check at the highest point of the curve): Vector3 BallisticVel(Vector3 target, float angle) { Vector3 dir = target - transform.position; // get target direction float h = dir.y; // get height difference dir.y = 0; // retain only the horizontal direction float dist = dir.magnitude ; // get horizontal distance float a = angle * Mathf.Deg2Rad; // convert angle to radians dir.y = dist * Mathf.Tan(a); // set dir to the elevation angle dist += h / Mathf.Tan(a); // correct for small height differences // calculate the velocity magnitude float vel = Mathf.Sqrt(dist * Physics.gravity.magnitude / Mathf.Sin(2 * a)); return vel * dir.normalized; } Vector3 TrajectoryPoint(Vector3 startingPosition, Vector3 startingVelocity, float n ) { float t = 1/60 ; // seconds per time step Vector3 stepVelocity = t * startingVelocity; // m/s Vector3 stepGravity = t * t * Physics.gravity; // m/s/s return startingPosition + n * stepVelocity + 0.5f * (n*n+n) * stepGravity; } bool CheckTrajectory(Vector3 startingPosition,Vector3 target, float angle_jump) { Debug.Log("checking"); if(angle_jump < 80f) { Debug.Log("if"); Vector3 startingVelocity = BallisticVel(target, angle_jump); for (int i = 0; i < 180; i++) { //Debug.Log(i); Vector3 trajectoryPosition = TrajectoryPoint( startingPosition, startingVelocity, i ); if(Physics.Raycast(trajectoryPosition,Vector3.forward,safeDistance)) { angle_jump += 10; break; // restart loop with the new angle } else continue; } return true; JumpVelocity = BallisticVel(target, angle_jump); } return false; }

    Read the article

  • Why are some of my view not aligned correctly at the bottom of my relative layout?

    - by Janusz
    I have problems getting some of my views aligned in a relative layout that I use inside a row of my listview. Here is a screenshot from the layout builder in Eclipse, this is what I think it should look like: The next image is from the emulator. Now the TestTestTest View is at the top and covers the name and distance Textviews. This is my layout: <?xml version="1.0" encoding="utf-8"?> <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="fill_parent" android:layout_height="fill_parent" android:padding="4dip"> <ImageView android:id="@+id/logo" android:layout_width="wrap_content" android:layout_height="wrap_content" android:adjustViewBounds="true" android:scaleType="centerInside" android:src="@drawable/icon" android:layout_centerVertical="true" android:layout_alignParentLeft="true" android:background="@color/green" /> <TextView android:id="@+id/distance" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="Distance" android:layout_alignParentRight="true" android:layout_alignParentTop="true" android:paddingRight="4dip" android:background="#000000" /> <TextView android:id="@+id/name" android:layout_width="fill_parent" style="@style/ListHeadText" android:layout_height="wrap_content" android:text="Name" android:layout_alignTop="@id/distance" android:layout_toRightOf="@id/logo" android:layout_toLeftOf="@id/distance" android:gravity="clip_horizontal" android:lines="1" android:paddingLeft="4dip" android:background="@color/red" /> <TextView android:id="@+id/number" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="Number" android:paddingRight="4dip" android:layout_alignRight="@id/distance" android:background="@color/darkred" android:layout_below="@id/distance" /> <TextView android:id="@+id/subcategory" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="Subcategory" android:paddingLeft="4dip" android:layout_alignLeft="@id/name" android:lines="1" android:gravity="clip_horizontal" android:layout_below="@id/distance" android:background="@color/green" /> <TextView android:id="@+id/test" android:layout_width="fill_parent" android:layout_height="wrap_content" android:text="TestTestTest" android:paddingLeft="4dip" android:layout_alignParentBottom="true" android:gravity="bottom" android:background="@color/red" /> Shouldnt align_parent_bottom put the view at the bottom of the cell in the list?

    Read the article

  • Ellipsize not working for textView inside custom listView

    - by aspartame
    Hi, I have a listView with custom objects defined by the xml-layout below. I want the textView with id "info" to be ellipsized on a single line, and I've tried using the attributes android:singleLine="true" android:ellipsize="end" without success. If I set the layout_width to a fixed width like e.g. android:layout_width="100px" the text is truncated fine. But for portability reasons this is not an acceptable solution. Can you spot the problem? <?xml version="1.0" encoding="utf-8"?> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:orientation="vertical" android:layout_width="fill_parent" android:layout_height="wrap_content" android:paddingBottom="5px" > <TextView android:id="@+id/destination" android:layout_width="fill_parent" android:layout_height="wrap_content" android:textSize="22dp" android:paddingLeft="5px" /> <TextView android:id="@+id/date" android:layout_width="fill_parent" android:layout_height="wrap_content" android:textSize="15dp" android:paddingLeft="5px" /> <TableLayout xmlns:android="http://schemas.android.com/apk/res/android" android:id="@+id/info_table" android:layout_width="fill_parent" android:layout_height="fill_parent" android:paddingLeft="5px" android:paddingTop="10px" > <TableRow> <TextView android:id="@+id/driver_label" android:gravity="right" android:paddingRight="5px" android:text="@string/driver_label" /> <TextView android:id="@+id/driver" /> </TableRow> <TableRow> <TextView android:id="@+id/passenger_label" android:gravity="right" android:paddingRight="5px" android:text="@string/passenger_label" /> <TextView android:id="@+id/passengers" /> </TableRow> <TableRow> <TextView android:id="@+id/info_label" android:gravity="right" android:paddingRight="5px" android:text="@string/info_label"/> <TextView android:id="@+id/info" android:layout_width="fill_parent" android:singleLine="true" android:ellipsize="end" /> </TableRow> </TableLayout>

    Read the article

  • android checkbox box issue

    - by raqz
    i have this check box in a alertdialog. when i try to check the state of the checkbox, the application force closes. any idea why? LayoutInflater factory = LayoutInflater.from(NewActivity.this); final View textDisplayView = factory.inflate(R.layout.nearestlocs, null); final AlertDialog.Builder newAlert = new AlertDialog.Builder(NewActivity.this); newAlert.setView(textDisplayView); final CheckBox checkBoxLab = (CheckBox) findViewById(R.id.checkboxlab); newAlert.setPositiveButton("Display on Map", new DialogInterface.OnClickListener() { public void onClick(DialogInterface dialog, int whichButton) { if(checkBoxLab.isChecked()){ libDisplayFlag = true; } error log 03-13 08:01:58.273: ERROR/AndroidRuntime(6188): Uncaught handler: thread main exiting due to uncaught exception 03-13 08:01:58.292: ERROR/AndroidRuntime(6188): java.lang.NullPointerException 03-13 08:01:58.292: ERROR/AndroidRuntime(6188): at com.isproj3.NewActivity$3.onClick(NewActivity.java:158) 03-13 08:01:58.292: ERROR/AndroidRuntime(6188): at com.android.internal.app.AlertController$ButtonHandler.handleMessage(AlertController.java:158) 03-13 08:01:58.292: ERROR/AndroidRuntime(6188): at android.os.Handler.dispatchMessage(Handler.java:99) xml <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:orientation="vertical" android:layout_width="fill_parent" android:layout_height="fill_parent"> <LinearLayout android:orientation="horizontal" android:gravity="center" android:layout_width="fill_parent" android:layout_height="fill_parent" android:layout_weight="1"> <CheckBox android:id="@+id/checkboxlib" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="Library" android:gravity="left" android:textColor="#FF0000" android:paddingBottom="5px" android:textSize="07pt" android:checked="true" /> <TextView android:id="@+id/librarytext" android:layout_width="wrap_content" android:layout_height="wrap_content" android:gravity="center" android:paddingBottom="5px" android:textSize="8pt" /> </LinearLayout> </LinearLayout>

    Read the article

  • Android how to use checkedtextview

    - by erdomester
    the title speaks for itself. I am over several articles, topics and still haven't figured out how to use checkedtextview. I want a listview with checkable items. In the following code i am using a listview and populating it with a string array. But how to change it to checkedtextview? delete.xml: <?xml version="1.0" encoding="utf-8"?> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:paddingTop="4dip" android:layout_width="fill_parent" android:layout_height="wrap_content" android:orientation="horizontal" android:id="@+id/linlay0" android:background="@color/list_bg"> <TextView android:id="@+id/TextView00" android:layout_width="fill_parent" android:layout_height="wrap_content" android:background="#D8D8D8" android:textColor="#424242" android:gravity="center_horizontal|center_vertical" android:textSize="20px" android:height="40px" android:textStyle="bold" /> <ListView android:id="@+id/ListView01" android:layout_width="wrap_content" android:layout_height="wrap_content" /> </LinearLayout> delete_lv.xml: <?xml version="1.0" encoding="utf-8"?> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:gravity="center_vertical" android:layout_width="fill_parent" android:layout_height="fill_parent"> <TextView android:id="@+id/list_content" android:textColor="#222222" android:gravity="center" android:text="sample" android:layout_margin="4dip" android:layout_width="wrap_content" android:layout_height="wrap_content" /> </LinearLayout> Delete.java: public class Delete extends Activity { ListView lv1; ArrayAdapter<String> adapter1; private String lv_items[] = { "Android", "iPhone", "BlackBerry", "AndroidPeople", "J2ME", "Listview", "ArrayAdapter", "ListItem", "Us", "UK", "India" }; @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.delete); TextView tv0 = (TextView)findViewById(R.id.TextView00); tv0.setText("Deletes"); lv1 = (ListView) findViewById(R.id.ListView01); adapter1 = new ArrayAdapter<String>(Delete.this,R.layout.list_black_text,R.id.list_content, lv_items); lv1.setAdapter(adapter1); adapter1.notifyDataSetChanged(); } }

    Read the article

  • Change TextView without completely re-drawing layout?

    - by twk
    I've found that updating a text view every second in my app burns a lot of CPU. The textview is in a horizontal LinearLayout, which is in turn inside of a vertical LinearLayout. Switching to a RelativeLayout (as recommended to increase perf) is not an option right now (I tried to get that working originally, but it was too complicated). The horizontal LinearLayout has 3 elements. The outer ones are TextViews with a layout_weight of 0, and the middle one is a progress bar with a layout_weight of 1 to make it expand to take up most of the space. I'm changing the contents of the leftmost TextView every second So, is there a way to change the contents of the text view without re-drawing everything? Or, can I force the TextViews to use a fixed amount of space to simplify the layout. Other tips for speeding up a LinearLayout are greatly appreciated as well. For reference, here is my entire layout. The field I'm updating is the timeIn one. <?xml version="1.0" encoding="utf-8"?> <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="wrap_content" android:layout_height="wrap_content"> <TextView android:text="Artist Name" android:id="@+id/curArtist" android:textSize="8pt" android:layout_width="fill_parent" android:layout_height="wrap_content" android:gravity="center_horizontal" android:paddingTop="5dp"></TextView> <TextView android:text="Song Name" android:id="@+id/curSong" android:textSize="10pt" android:textStyle="bold" android:layout_below="@id/curArtist" android:layout_width="fill_parent" android:layout_height="wrap_content" android:gravity="center_horizontal"></TextView> <TextView android:text="Album Name" android:id="@+id/curAlbum" android:textSize="8pt" android:layout_below="@id/curSong" android:layout_width="fill_parent" android:layout_height="wrap_content" android:gravity="center_horizontal"></TextView> <LinearLayout android:layout_width="fill_parent" android:layout_height="fill_parent" android:layout_below="@id/curAlbum" android:orientation="vertical"> <LinearLayout android:id="@+id/seekWrapper" android:layout_width="fill_parent" android:layout_height="wrap_content" android:minHeight="10dp" android:maxHeight="10dp" android:orientation="horizontal"> <TextView android:text="0:00" android:id="@+id/timeIn" android:textSize="4pt" android:paddingLeft="10dp" android:gravity="center_vertical" android:layout_weight="0" android:layout_gravity="left|center_vertical" android:layout_width="wrap_content" android:layout_height="fill_parent"></TextView> <ProgressBar android:layout_below="@id/curAlbum" android:id="@+id/progressBar" android:paddingLeft="7dp" android:paddingRight="7dp" android:layout_width="fill_parent" android:layout_height="fill_parent" android:maxHeight="10dp" android:minHeight="10dp" android:indeterminate="false" android:layout_weight="1" android:layout_gravity="center_horizontal|center_vertical" style="?android:attr/progressBarStyleHorizontal"></ProgressBar> <TextView android:text="0:00" android:id="@+id/timeLeft" android:paddingRight="10dp" android:textSize="4pt" android:layout_gravity="right|center_vertical" android:layout_weight="0" android:layout_width="wrap_content" android:layout_height="fill_parent"></TextView> </LinearLayout> <ImageView android:id="@+id/albumArt" android:layout_weight="1" android:padding="5dp" android:layout_width="fill_parent" android:layout_height="fill_parent" android:src="@drawable/blank_album_art"></ImageView> <LinearLayout android:layout_width="fill_parent" android:layout_height="wrap_content" android:orientation="horizontal" > <ImageButton android:id="@+id/prev" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_gravity="left" android:src="@drawable/button_prev" android:paddingLeft="10dp" android:background="@null"></ImageButton> <ImageButton android:id="@+id/playPause" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_gravity="center_horizontal" android:src="@drawable/button_play" android:layout_weight="1" android:background="@null"></ImageButton> <ImageButton android:id="@+id/next" android:layout_width="wrap_content" android:layout_height="wrap_content" android:src="@drawable/button_next" android:layout_gravity="right" android:paddingRight="10dp" android:background="@null"></ImageButton> </LinearLayout> </LinearLayout> </RelativeLayout>

    Read the article

  • Collision detection with multiple polygons simultaneously

    - by Craig Innes
    I've written a collision system which detects/resolves collisions between a rectangular player and a convex polygon world using the Separating Axis Theorem. This scheme works fine when the player is colliding with a single polygon, but when I try to create a level made up of combinations of these shapes, the player gets "stuck" between shapes when trying to move from one polygon to the other. The reason for this seems to be that collisions are detected after the player has been pushed through the shape by its movement or gravity. When the system resolves the collision, it resolves them in an order that doesn't make sense (for example, when the player is moving from one flat rectangle to another, gravity pushes them below the ground, but the collision with the left hand side of the second block is resolved before the collision with the top of the block, meaning the player is pushed back left before being pushed back up). Other similar posts have resolved this problem by having a strict rule on which axes to resolve first. For example, always resolve the collision on the y axis, then if the object is still colliding with things, resolve on the x axis. This solution only works in the case of a completely axis oriented box world, and doesn't solve the problem if the player is stuck moving along a series of angled shapes or sliding down a wall. Does any one have any ideas of how I could alter my collision system to prevent these situations from happening?

    Read the article

  • Modded Portal Gun Levitates a Companion Cube [Video]

    - by Jason Fitzpatrick
    This cleverly designed Portal gun prop levitates a model Companion Cube; the whole setup just begs to be paired with a Halloween costume. Courtesy of Caleb over at Hack A Day: I was out to lunch with a couple friends, brainstorming ideas for fun projects when one of them says “Wouldn’t it be cool if we could build a working gravity gun?”. We all immediately concurred that while it would in fact be cool, it is also a silly proposition. However, only a few seconds later, I realized we could do a display piece that emulated this concept very easily. Floating magnetic globes have been around for quite some time. I determined I would tear the guts out of a stock floating globe and mount it on a portal gun, since they’re easier to find than a gravity gun. I would also build a custom companion cube to be the correct size and weight necessary. Watch the video above and then check out the link below for more information on the build. HTG Explains: What is the Windows Page File and Should You Disable It? How To Get a Better Wireless Signal and Reduce Wireless Network Interference How To Troubleshoot Internet Connection Problems

    Read the article

  • Engine for 2D Top-Down Physics-Based Skeletal Animation

    - by RylandAlmanza
    I just watched at the Sui Generis video, and was completely amazed. Specifically, the part where the big troll thing is beating up the player with his flail. This got me really excited, and I would like to try implementing something like this in a 2D Top-Down format. Something like this. That atloria example seems simple enough, but it's not exactly what I'm looking to make. I think atloria is using predefined animations, where as I would like to make something more physics-based like the Sui Generis engine does. So, I'm wondering what physics engines might work for something like this, and if I'd need to implement my own skeletal system, or if I could just use "joints" and such from the engine. The only experience I have in terms of physics engines is Box2D, which I've heard shouldn't be used for top-down settings, and I can think of a few reasons it wouldn't work out well. One of those reasons being gravity. In box 2D, gravity pulls towards a side of the screen (usually the bottom.) I wouldn't want my player's forearms constantly being pulled to one side. :) Also should mention that the programming language doesn't matter all that much to me. I'm currently playing with HTML5 stuff, though. :) Thanks in advance!

    Read the article

  • Collider2D and Rigidbody2D, how do they work?

    - by user42646
    I have been learning JavaScript and Unity for a week now. I learned how to make Cube as a Ground and another Cube as a player and I used this code to make the Player Cube move forward and backward and jumping var walkspeed: float = 5.0; var jumpheight: float = 250.0; var grounded = false; function Update() { rigidbody.freezeRotation = true; if (Input.GetKey("a")) transform.Translate(Vector3(-1, 0, 0) * Time.deltaTime * walkspeed); if (Input.GetKey("d")) transform.Translate(Vector3(1, 0, 0) * Time.deltaTime * walkspeed); if (Input.GetButton("Jump")) { Jump(); } } function OnCollisionEnter(hit: Collision) { grounded = true; } function Jump() { if (grounded == true) { rigidbody.AddForce(Vector3.up * jumpheight); grounded = false; } } I also learned how to make a character hit box. how to make a sprite and animation. pretty much the basic stuff. Couple of days ago I created simple ground in Photoshop and a simple character and imported them to Unity3D. Whenever I use my code above the character keeps falling from the scene. Like the character has nothing to stand on. After thinking about it it make sense because I really didn't make anything to make the player character understand that he should stand on something so I started reading about this issue and I realized that there is something called Collider2D and Rigidbody2D. Now I'm really stuck here I just don't know what to do. I applied the rigibody2d to my character picture and the Collider2D to the ground picture but whenever I play the project the gravity makes my character falls down. This is my question: How can I make the rigibody2d object realize that it shouldn't fall if there is a Collider2D object under it? So when I jump it's going to jump and the gravity going to bring it back to the ground.

    Read the article

  • Form, function and complexity in rule processing

    - by Charles Young
    Tim Bass posted on ‘Orwellian Event Processing’. I was involved in a heated exchange in the comments, and he has more recently published a post entitled ‘Disadvantages of Rule-Based Systems (Part 1)’. Whatever the rights and wrongs of our exchange, it clearly failed to generate any agreement or understanding of our different positions. I don't particularly want to promote further argument of that kind, but I do want to take the opportunity of offering a different perspective on rule-processing and an explanation of my comments. For me, the ‘red rag’ lay in Tim’s claim that “...rules alone are highly inefficient for most classes of (not simple) problems” and a later paragraph that appears to equate the simplicity of form (‘IF-THEN-ELSE’) with simplicity of function.   It is not the first time Tim has expressed these views and not the first time I have responded to his assertions.   Indeed, Tim has a long history of commenting on the subject of complex event processing (CEP) and, less often, rule processing in ‘robust’ terms, often asserting that very many other people’s opinions on this subject are mistaken.   In turn, I am of the opinion that, certainly in terms of rule processing, which is an area in which I have a specific interest and knowledge, he is often mistaken. There is no simple answer to the fundamental question ‘what is a rule?’ We use the word in a very fluid fashion in English. Likewise, the term ‘rule processing’, as used widely in IT, is equally difficult to define simplistically. The best way to envisage the term is as a ‘centre of gravity’ within a wider domain. That domain contains many other ‘centres of gravity’, including CEP, statistical analytics, neural networks, natural language processing and so much more. Whole communities tend to gravitate towards and build themselves around some of these centres. The term 'rule processing' is associated with many different technology types, various software products, different architectural patterns, the functional capability of many applications and services, etc. There is considerable variation amongst these different technologies, techniques and products. Very broadly, a common theme is their ability to manage certain types of processing and problem solving through declarative, or semi-declarative, statements of propositional logic bound to action-based consequences. It is generally important to be able to decouple these statements from other parts of an overall system or architecture so that they can be managed and deployed independently.  As a centre of gravity, ‘rule processing’ is no island. It exists in the context of a domain of discourse that is, itself, highly interconnected and continuous.   Rule processing does not, for example, exist in splendid isolation to natural language processing.   On the contrary, an on-going theme of rule processing is to find better ways to express rules in natural language and map these to executable forms.   Rule processing does not exist in splendid isolation to CEP.   On the contrary, an event processing agent can reasonably be considered as a rule engine (a theme in ‘Power of Events’ by David Luckham).   Rule processing does not live in splendid isolation to statistical approaches such as Bayesian analytics. On the contrary, rule processing and statistical analytics are highly synergistic.   Rule processing does not even live in splendid isolation to neural networks. For example, significant research has centred on finding ways to translate trained nets into explicit rule sets in order to support forms of validation and facilitate insight into the knowledge stored in those nets. What about simplicity of form?   Many rule processing technologies do indeed use a very simple form (‘If...Then’, ‘When...Do’, etc.)   However, it is a fundamental mistake to equate simplicity of form with simplicity of function.   It is absolutely mistaken to suggest that simplicity of form is a barrier to the efficient handling of complexity.   There are countless real-world examples which serve to disprove that notion.   Indeed, simplicity of form is often the key to handling complexity. Does rule processing offer a ‘one size fits all’. No, of course not.   No serious commentator suggests it does.   Does the design and management of large knowledge bases, expressed as rules, become difficult?   Yes, it can do, but that is true of any large knowledge base, regardless of the form in which knowledge is expressed.   The measure of complexity is not a function of rule set size or rule form.  It tends to be correlated more strongly with the size of the ‘problem space’ (‘search space’) which is something quite different.   Analysis of the problem space and the algorithms we use to search through that space are, of course, the very things we use to derive objective measures of the complexity of a given problem. This is basic computer science and common practice. Sailing a Dreadnaught through the sea of information technology and lobbing shells at some of the islands we encounter along the way does no one any good.   Building bridges and causeways between islands so that the inhabitants can collaborate in open discourse offers hope of real progress.

    Read the article

  • LIBGDX "parsing error emitter" with 2 or more emitters [on hold]

    - by flow969
    I have a problem with the use of particle effect of LIBGDX with 2 or more emitters. After using ParticleEditor to create my .p file, I use it in my code BUT...when I use only 1 emitter it's fine but with more than 1, not fine ! :( Here is my error code in java console : Exception in thread "LWJGL Application" java.lang.RuntimeException: Error parsing emitter: - Delay - at com.badlogic.gdx.graphics.g2d.ParticleEmitter.load(ParticleEmitter.java:910) at com.badlogic.gdx.graphics.g2d.ParticleEmitter.<init>(ParticleEmitter.java:95) at com.badlogic.gdx.graphics.g2d.ParticleEffect.loadEmitters(ParticleEffect.java:154) at com.badlogic.gdx.graphics.g2d.ParticleEffect.load(ParticleEffect.java:138) at com.fasgame.fishtrip.android.screens.GameScreen.show(GameScreen.java:313) at com.badlogic.gdx.Game.setScreen(Game.java:61) at com.fasgame.fishtrip.android.screens.MainMenuScreen.render(MainMenuScreen.java:71) at com.badlogic.gdx.Game.render(Game.java:46) at com.badlogic.gdx.backends.lwjgl.LwjglApplication.mainLoop(LwjglApplication.java:206) at com.badlogic.gdx.backends.lwjgl.LwjglApplication$1.run(LwjglApplication.java:114) Caused by: java.lang.NumberFormatException: For input string: "- Count -" at sun.misc.FloatingDecimal.readJavaFormatString(Unknown Source) at sun.misc.FloatingDecimal.parseFloat(Unknown Source) at java.lang.Float.parseFloat(Unknown Source) at com.badlogic.gdx.graphics.g2d.ParticleEmitter.readFloat(ParticleEmitter.java:929) at com.badlogic.gdx.graphics.g2d.ParticleEmitter$RangedNumericValue.load(ParticleEmitter.java:1062) at com.badlogic.gdx.graphics.g2d.ParticleEmitter.load(ParticleEmitter.java:866) ... 9 more And here is my particle effect .p file : Blanc - Delay - active: false - Duration - lowMin: 3000.0 lowMax: 3000.0 - Count - min: 0 max: 200 - Emission - lowMin: 0.0 lowMax: 0.0 highMin: 250.0 highMax: 250.0 relative: false scalingCount: 1 scaling0: 1.0 timelineCount: 1 timeline0: 0.0 - Life - lowMin: 500.0 lowMax: 500.0 highMin: 500.0 highMax: 500.0 relative: false scalingCount: 3 scaling0: 1.0 scaling1: 0.47058824 scaling2: 0.0 timelineCount: 3 timeline0: 0.0 timeline1: 0.51369864 timeline2: 1.0 - Life Offset - active: false - X Offset - active: false - Y Offset - active: false - Spawn Shape - shape: point - Spawn Width - lowMin: 0.0 lowMax: 0.0 highMin: 0.0 highMax: 0.0 relative: false scalingCount: 1 scaling0: 1.0 timelineCount: 1 timeline0: 0.0 - Spawn Height - lowMin: 0.0 lowMax: 0.0 highMin: 0.0 highMax: 0.0 relative: false scalingCount: 1 scaling0: 1.0 timelineCount: 1 timeline0: 0.0 - Scale - lowMin: 0.0 lowMax: 0.0 highMin: 70.0 highMax: 70.0 relative: true scalingCount: 2 scaling0: 1.0 scaling1: 0.0 timelineCount: 2 timeline0: 0.0 timeline1: 1.0 - Velocity - active: true lowMin: 0.0 lowMax: 0.0 highMin: 30.0 highMax: 300.0 relative: false scalingCount: 1 scaling0: 1.0 timelineCount: 1 timeline0: 0.0 - Angle - active: true lowMin: 220.0 lowMax: 320.0 highMin: 220.0 highMax: 320.0 relative: false scalingCount: 2 scaling0: 0.0 scaling1: 0.98039216 timelineCount: 2 timeline0: 0.0 timeline1: 1.0 - Rotation - active: false - Wind - active: false - Gravity - active: true lowMin: 0.0 lowMax: 0.0 highMin: 0.0 highMax: 0.0 relative: false scalingCount: 1 scaling0: 1.0 timelineCount: 1 timeline0: 0.0 - Tint - colorsCount: 3 colors0: 0.50980395 colors1: 0.7647059 colors2: 0.7921569 timelineCount: 1 timeline0: 0.0 - Transparency - lowMin: 0.0 lowMax: 0.0 highMin: 1.0 highMax: 1.0 relative: false scalingCount: 4 scaling0: 1.0 scaling1: 1.0 scaling2: 1.0 scaling3: 1.0 timelineCount: 4 timeline0: 0.0 timeline1: 0.36301368 timeline2: 0.6164383 timeline3: 1.0 - Options - attached: false continuous: true aligned: false additive: true behind: false premultipliedAlpha: false pre_particle.png Bleu - Delay - active: false - Duration - lowMin: 3000.0 lowMax: 3000.0 - Count - min: 0 max: 200 - Emission - lowMin: 0.0 lowMax: 0.0 highMin: 250.0 highMax: 250.0 relative: false scalingCount: 1 scaling0: 1.0 timelineCount: 1 timeline0: 0.0 - Life - lowMin: 500.0 lowMax: 500.0 highMin: 500.0 highMax: 500.0 relative: false scalingCount: 3 scaling0: 1.0 scaling1: 0.47058824 scaling2: 0.0 timelineCount: 3 timeline0: 0.0 timeline1: 0.51369864 timeline2: 1.0 - Life Offset - active: false - X Offset - active: false - Y Offset - active: false - Spawn Shape - shape: point - Spawn Width - lowMin: 0.0 lowMax: 0.0 highMin: 0.0 highMax: 0.0 relative: false scalingCount: 1 scaling0: 1.0 timelineCount: 1 timeline0: 0.0 - Spawn Height - lowMin: 0.0 lowMax: 0.0 highMin: 0.0 highMax: 0.0 relative: false scalingCount: 1 scaling0: 1.0 timelineCount: 1 timeline0: 0.0 - Scale - lowMin: 0.0 lowMax: 0.0 highMin: 70.0 highMax: 70.0 relative: true scalingCount: 2 scaling0: 1.0 scaling1: 0.0 timelineCount: 2 timeline0: 0.0 timeline1: 1.0 - Velocity - active: true lowMin: 0.0 lowMax: 0.0 highMin: 30.0 highMax: 300.0 relative: false scalingCount: 1 scaling0: 1.0 timelineCount: 1 timeline0: 0.0 - Angle - active: true lowMin: 220.0 lowMax: 320.0 highMin: 220.0 highMax: 320.0 relative: false scalingCount: 2 scaling0: 0.0 scaling1: 0.98039216 timelineCount: 2 timeline0: 0.0 timeline1: 1.0 - Rotation - active: false - Wind - active: false - Gravity - active: true lowMin: 0.0 lowMax: 0.0 highMin: 0.0 highMax: 0.0 relative: false scalingCount: 1 scaling0: 1.0 timelineCount: 1 timeline0: 0.0 - Tint - colorsCount: 3 colors0: 0.0 colors1: 0.7254902 colors2: 0.7921569 timelineCount: 1 timeline0: 0.0 - Transparency - lowMin: 0.0 lowMax: 0.0 highMin: 1.0 highMax: 1.0 relative: false scalingCount: 6 scaling0: 0.0 scaling1: 1.0 scaling2: 1.0 scaling3: 1.0 scaling4: 1.0 scaling5: 0.0 timelineCount: 6 timeline0: 0.0 timeline1: 0.047945205 timeline2: 0.34246576 timeline3: 0.6712329 timeline4: 0.94520545 timeline5: 1.0 - Options - attached: false continuous: true aligned: false additive: true behind: false premultipliedAlpha: false pre_particle.png BleuFonce - Delay - active: false - Duration - lowMin: 3000.0 lowMax: 3000.0 - Count - min: 0 max: 200 - Emission - lowMin: 0.0 lowMax: 0.0 highMin: 250.0 highMax: 250.0 relative: false scalingCount: 1 scaling0: 1.0 timelineCount: 1 timeline0: 0.0 - Life - lowMin: 500.0 lowMax: 500.0 highMin: 500.0 highMax: 500.0 relative: false scalingCount: 3 scaling0: 1.0 scaling1: 0.47058824 scaling2: 0.0 timelineCount: 3 timeline0: 0.0 timeline1: 0.51369864 timeline2: 1.0 - Life Offset - active: false - X Offset - active: false - Y Offset - active: false - Spawn Shape - shape: point - Spawn Width - lowMin: 0.0 lowMax: 0.0 highMin: 0.0 highMax: 0.0 relative: false scalingCount: 1 scaling0: 1.0 timelineCount: 1 timeline0: 0.0 - Spawn Height - lowMin: 0.0 lowMax: 0.0 highMin: 0.0 highMax: 0.0 relative: false scalingCount: 1 scaling0: 1.0 timelineCount: 1 timeline0: 0.0 - Scale - lowMin: 0.0 lowMax: 0.0 highMin: 70.0 highMax: 70.0 relative: true scalingCount: 2 scaling0: 1.0 scaling1: 0.0 timelineCount: 2 timeline0: 0.0 timeline1: 1.0 - Velocity - active: true lowMin: 0.0 lowMax: 0.0 highMin: 30.0 highMax: 300.0 relative: false scalingCount: 1 scaling0: 1.0 timelineCount: 1 timeline0: 0.0 - Angle - active: true lowMin: 220.0 lowMax: 320.0 highMin: 220.0 highMax: 320.0 relative: false scalingCount: 2 scaling0: 0.0 scaling1: 0.98039216 timelineCount: 2 timeline0: 0.0 timeline1: 1.0 - Rotation - active: false - Wind - active: false - Gravity - active: true lowMin: 0.0 lowMax: 0.0 highMin: 0.0 highMax: 0.0 relative: false scalingCount: 1 scaling0: 1.0 timelineCount: 1 timeline0: 0.0 - Tint - colorsCount: 3 colors0: 0.0 colors1: 0.7294118 colors2: 1.0 timelineCount: 1 timeline0: 0.0 - Transparency - lowMin: 0.0 lowMax: 0.0 highMin: 1.0 highMax: 1.0 relative: false scalingCount: 4 scaling0: 1.0 scaling1: 0.0 scaling2: 0.0 scaling3: 1.0 timelineCount: 4 timeline0: 0.0 timeline1: 0.001 timeline2: 0.5753425 timeline3: 0.79452056 - Options - attached: false continuous: true aligned: false additive: true behind: false premultipliedAlpha: false pre_particle.png For the "- Image Path -" missing it's normal if I let them in it doesn't work even with only 1 emitter PS : I've already updated my lib to the last release

    Read the article

  • Trouble with AABB collision response and physics

    - by WCM
    I have been racking my brain trying to figure out a problem I am having with physics and basic AABB collision response. I am fairly close as the physics are mostly right. Gravity feels good and movement is solid. The issue I am running into is that when I land on the test block in my project, I can jump off of it most of the time. If I repeatedly jump in place, I will eventually get stuck one or two pixels below the surface of the test block. If I try to jump, I can become free of the other block, but it will happen again a few jumps later. I feel like I am missing something really obvious with this. I have two functions that support the detection and function to return a vector for the overlap of the two rectangle bounding boxes. I have a single update method that is processing the physics and collision for the entity. I feel like I am missing something very simple, like an ordering of the physics vs. collision response handling. Any thoughts or help can be appreciated. I apologize for the format of the code, tis prototype code mostly. The collision detection function: public static bool Collides(Rectangle source, Rectangle target) { if (source.Right < target.Left || source.Bottom < target.Top || source.Left > target.Right || source.Top > target.Bottom) { return false; } return true; } The overlap function: public static Vector2 GetMinimumTranslation(Rectangle source, Rectangle target) { Vector2 mtd = new Vector2(); Vector2 amin = source.Min(); Vector2 amax = source.Max(); Vector2 bmin = target.Min(); Vector2 bmax = target.Max(); float left = (bmin.X - amax.X); float right = (bmax.X - amin.X); float top = (bmin.Y - amax.Y); float bottom = (bmax.Y - amin.Y); if (left > 0 || right < 0) return Vector2.Zero; if (top > 0 || bottom < 0) return Vector2.Zero; if (Math.Abs(left) < right) mtd.X = left; else mtd.X = right; if (Math.Abs(top) < bottom) mtd.Y = top; else mtd.Y = bottom; // 0 the axis with the largest mtd value. if (Math.Abs(mtd.X) < Math.Abs(mtd.Y)) mtd.Y = 0; else mtd.X = 0; return mtd; } The update routine (gravity = 0.001f, jumpHeight = 0.35f, moveAmount = 0.15f): public void Update(GameTime gameTime) { Acceleration.Y = gravity; Position += new Vector2((float)(movement * moveAmount * gameTime.ElapsedGameTime.TotalMilliseconds), (float)(Velocity.Y * gameTime.ElapsedGameTime.TotalMilliseconds)); Velocity.Y += Acceleration.Y; Vector2 previousPosition = new Vector2((int)Position.X, (int)Position.Y); KeyboardState keyboard = Keyboard.GetState(); movement = 0; if (keyboard.IsKeyDown(Keys.Left)) { movement -= 1; } if (keyboard.IsKeyDown(Keys.Right)) { movement += 1; } if (Position.Y + 16 > GameClass.Instance.GraphicsDevice.Viewport.Height) { Velocity.Y = 0; Position = new Vector2(Position.X, GameClass.Instance.GraphicsDevice.Viewport.Height - 16); IsOnSurface = true; } if (Collision.Collides(BoundingBox, GameClass.Instance.block.BoundingBox)) { Vector2 mtd = Collision.GetMinimumTranslation(BoundingBox, GameClass.Instance.block.BoundingBox); Position += mtd; Velocity.Y = 0; IsOnSurface = true; } if (keyboard.IsKeyDown(Keys.Space) && !previousKeyboard.IsKeyDown(Keys.Space)) { if (IsOnSurface) { Velocity.Y = -jumpHeight; IsOnSurface = false; } } previousKeyboard = keyboard; } This is also a full download to the project. https://www.box.com/s/3rkdtbso3xgfgc2asawy P.S. I know that I could do this with the XNA Platformer Starter Kit algo, but it has some deep flaws that I am going to try to live without. I'd rather go the route of collision response via an overlay function. Thanks for any and all insight!

    Read the article

  • Android TextView inside a ListView setTextHighlightColor() issue

    - by y ramesh rao
    I have Listview and Textview inside it now the thing is that i want to change the Text Color over the Selection of the that cell in the Listview but setting setTextHighlightColor of Textview is not giving this output I have tired setting a selector for this but that is not Heling too. Can this be solved. What might be causing the issue to populate. The Cell.xml is <ImageView android:id="@+id/thumbnail" android:layout_width="48dip" android:layout_height="48dip" android:layout_gravity="center_vertical" android:src="@drawable/icon" /> <TextView android:id="@+id/username" android:layout_width="fill_parent" android:layout_height="wrap_content" android:layout_toRightOf="@id/thumbnail" android:layout_alignParentTop="true" android:gravity="top" android:text="Username" android:textColor="@drawable/timeline_username_selector" /> <TextView android:id="@+id/time" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_alignParentRight="true" android:layout_marginLeft="10px" android:text="31stMarch,2010" android:textColor="@drawable/timeline_username_selector" /> <TextView android:id="@+id/textTweet" android:layout_width="fill_parent" android:layout_height="wrap_content" android:layout_below="@+id/username" android:layout_toRightOf="@id/thumbnail" android:layout_alignParentBottom="true" android:gravity="top" android:textColor="@drawable/timeline_tweet_selector" /> And the selector for the text color is something like this

    Read the article

  • Box2d: Maximum possible linear velocity?

    - by Rosarch
    I think I've configured Box2d to have some sort of maximum velocity for any body, but I'm not sure. I apply an impulse like (100000000, 100000000), and the body moves just as fast as (100, 100) - which is not that fast at all. My game is a top-down 2d. Here is some code that may be relevant: private readonly Vector2 GRAVITY = new Vector2(0, 0); public void initializePhysics(ContactReporter contactReporter) { world = new World(GRAVITY, true); IContactListener contactListener = contactReporter; world.ContactListener = contactListener; } public void Update(GameTime gameTime) { // ... worldState.PhysicsWorld.Step((float)gameTime.ElapsedGameTime.TotalSeconds, 10, 10); //... }

    Read the article

  • Why my button can trigger the UI to scroll and my TimerTask inside the activity can't?

    - by Spidey
    Long Story Short: a method of my activity updates and scrolls the ListView through an ArrayAdapter like it should, but a method of an internal TimerTask for polling messages (which are displayed in the ListView) updates the ListView, but don't scroll it. Why? Long Story: I have a chat activity with this layout: <?xml version="1.0" encoding="utf-8"?> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:orientation="vertical" android:layout_width="fill_parent" android:layout_height="fill_parent" android:background="#fff" > <ListView android:id="@+id/messageList" android:layout_width="fill_parent" android:layout_height="fill_parent" android:stackFromBottom="true" android:transcriptMode="alwaysScroll" android:layout_weight="1" android:fadeScrollbars="true" /> <LinearLayout android:orientation="horizontal" android:layout_width="fill_parent" android:layout_height="wrap_content" android:gravity="center" > <EditText android:id="@+id/message" android:layout_width="fill_parent" android:layout_height="wrap_content" android:layout_weight="1" /> <Button android:id="@+id/button_send" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="Send" android:onClick="sendMessage" /> </LinearLayout> </LinearLayout> The internal listView (with id messageList) is populated by an ArrayAdapter which inflates the XML below and replaces strings in it. <?xml version="1.0" encoding="utf-8"?> <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" android:orientation="vertical" android:layout_width="fill_parent" android:layout_height="wrap_content" android:clickable="false" android:background="#fff" android:paddingLeft="2dp" android:paddingRight="2dp" > <TextView xmlns:android="http://schemas.android.com/apk/res/android" android:id="@+id/date" android:layout_width="wrap_content" android:layout_height="wrap_content" android:textSize="16sp" android:textColor="#00F" android:typeface="monospace" android:text="2010-10-12 12:12:03" android:gravity="left" /> <TextView xmlns:android="http://schemas.android.com/apk/res/android" android:id="@+id/sender" android:layout_width="fill_parent" android:layout_height="wrap_content" android:textSize="16sp" android:textColor="#f84" android:text="spidey" android:gravity="right" android:textStyle="bold" /> <TextView xmlns:android="http://schemas.android.com/apk/res/android" android:id="@+id/body" android:layout_width="fill_parent" android:layout_height="wrap_content" android:textSize="14sp" android:padding="1dp" android:gravity="left" android:layout_below="@id/date" android:text="Mensagem muito legal 123 quatro cinco seis." android:textColor="#000" /> </RelativeLayout> The problem is: in the main layout, I have a EditText for the chat message, and a Button to send the message. I have declared the adapter in the activity scope: public class ChatManager extends Activity{ private EditText et; private ListView lv; private Timestamp lastDate = null; private long campaignId; private ChatAdapter ca; private List<ChatMessage> vetMsg = new ArrayList<ChatMessage>(); private Timer chatPollingTimer; private static final int CHAT_POLLING_PERIOD = 10000; ... } So, inside sendMessage(View v), the notifyDataSetChanged() scrolls the ListView acordingly, so I can see the latest chat messages automatically: public void sendMessage(View v) { String msg = et.getText().toString(); if(msg.length() == 0){ return; } et.setText(""); String xml = ServerCom.sendAndGetChatMessages(campaignId, lastDate, msg); Vector<ChatMessage> vetNew = Chat.parse(new InputSource(new StringReader(xml))); //Pegando a última data if(!vetNew.isEmpty()){ lastDate = vetNew.lastElement().getDateSent(); //Atualizando a tela vetMsg.addAll(vetNew); ca.notifyDataSetChanged(); } } But inside my TimerTask, I can't. The ListView IS UPDATED, but it just don't scroll automatically. What am I doing wrong? private class chatPollingTask extends TimerTask { @Override public void run() { String xml; if(lastDate != null){ //Chama o Updater xml = ServerCom.getChatMessages(campaignId, lastDate); }else{ //Chama o init denovo xml = ServerCom.getChatMessages(campaignId); } Vector<ChatMessage> vetNew = Chat.parse(new InputSource(new StringReader(xml))); if(!(vetNew.isEmpty())){ //TODO: descobrir porque o chat não está rolando quando chegam novas mensagens //Descobrir também como forçar o rolamento, enquanto o bug não for corrigido. Log.d("CHAT", "New message(s) acquired!"); lastDate = vetNew.lastElement().getDateSent(); vetMsg.addAll(vetNew); ca.notifyDataSetChanged(); } } } How can I force the scroll to the bottom? I've tried using scrollTo using lv.getBottom()-lv.getHeight(), but didn't work. Is this a bug in the Android SDK? Sorry for the MASSIVE amount of code, but I guess this way the question gets pretty clear.

    Read the article

  • android R.layout concept

    - by yoav.str
    can I genrate java code instead using xml code ? lets say i want to do this xml code in a loop : <TableRow android:id="@+id/LivingCreture" android:layout_width="wrap_content" android:layout_height="wrap_content"> <TextView android:text="LivingCreture" android:gravity="left" android:id="@+id/LivingCretureT" android:layout_width="45dp" android:layout_height="45dp"></TextView> <EditText android:text=" " android:gravity="center" android:id="@+id/LivingCretureE" android:layout_width="45dp" android:layout_height="45dp"></EditText> <ImageView android:id="@+id/ImageView03" android:layout_width="wrap_content"android:layout_height="wrap_content"></ImageView> is it possiable ?

    Read the article

  • Large margin by long title

    - by Kevin Koenen
    I try to show a list of offers. When an advertiser insert a large title, the margin of an item (offer) will be showed what shouldn't. I've tried different layouts but that doesn't work. Link to image :) You see, some of the items has a large margin. Here's the code: <?xml version="1.0" encoding="utf-8"?> <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" android:id="@+id/gallerylayout" android:layout_width="fill_parent" android:layout_height="fill_parent"> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_height="wrap_content" android:gravity="left|center" android:layout_width="wrap_content" android:paddingBottom="2dp" android:paddingTop="2dp" android:paddingLeft="5dp" android:background="#20000000" android:cacheColorHint="#00000000"> <ImageView android:id="@+id/ad_image_small" android:layout_width="wrap_content" android:layout_height="fill_parent" android:layout_marginRight="6dip" android:src="@drawable/ic_launcher"/> <LinearLayout android:orientation="vertical" android:layout_width="0dip" android:layout_weight="1" android:layout_height="fill_parent"> <TextView android:id="@+id/ad_id" android:visibility="gone" android:layout_width="wrap_content" android:layout_height="wrap_content"/> <TextView android:id="@+id/ad_img_url" android:visibility="gone" android:layout_width="wrap_content" android:layout_height="wrap_content"/> <LinearLayout android:orientation="horizontal" android:layout_width="fill_parent" android:layout_height="wrap_content"> <TextView android:id="@+id/ad_title" android:layout_width="wrap_content" android:layout_height="wrap_content" android:padding="3dp" android:gravity="left" android:textColor="#000000" android:ellipsize="end" android:singleLine="true"/> <TextView android:id="@+id/ad_km" android:layout_width="match_parent" android:layout_height="wrap_content" android:layout_margin="3dp" android:layout_marginBottom="1dp" android:textColor="#000000" android:gravity="right"/> </LinearLayout> <LinearLayout android:orientation="horizontal" android:layout_width="fill_parent" android:layout_height="wrap_content"> <TextView android:id="@+id/ad_text" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_marginLeft="3dp" android:textColor="#0099CC" android:ellipsize="end" android:singleLine="true"/> </LinearLayout> <LinearLayout android:orientation="horizontal" android:layout_width="fill_parent" android:layout_height="wrap_content" android:layout_margin="2dp" android:padding="5dp"> <ImageView android:id="@+id/ad_clock" android:layout_width="20dp" android:layout_height="20dp" android:layout_marginRight="5dip" android:src="@drawable/icon_clock"/> <ProgressBar android:id="@+id/progressbar" android:layout_width="match_parent" android:layout_height="8dp" android:layout_margin="5dp" android:paddingLeft="2dp" android:max="100" style="?android:attr/progressBarStyleHorizontal" android:progressDrawable="@drawable/color_progressbar" /> </LinearLayout> </LinearLayout> </LinearLayout> <ImageView android:id="@+id/overlay_image" android:background="#0000" android:src="@drawable/verlopen2x" android:layout_alignTop="@id/ad_image_small" android:layout_alignBottom="@id/ad_image_small" android:layout_width="fill_parent" android:layout_height="wrap_content" android:adjustViewBounds="true" android:visibility="visible" /> I can't see what i'm doing wrong. Thanks in advance!

    Read the article

  • How to do this layout? (Link on Image)

    - by Spredzy
    Hi all, I was wondering how to obtain this result : http://img718.imageshack.us/img718/6173/screenshot20100411at126.png This is what I tried : <RelativeLayout android:layout_width="fill_parent" android:layout_height="wrap_content" android:background="#CCCCCC" android:orientation="horizontal" android:layout_weight="0"> <Button android:id="@+id/btn_cancel" android:text="@string/cancel" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_margin="5px" android:gravity="left" /> <Button android:id="@+id/btn_save" android:text="@string/save" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_margin="5px" android:layout_toRightOf="@id/btn_cancel" android:gravity="right"/> </RelativeLayout> I tried to play with the layout_width properties and setting them up to fill parents both of them but did not work, if anyone has an idea ... Thank you !

    Read the article

< Previous Page | 1 2 3 4 5 6 7 8 9 10 11 12  | Next Page >